Q. The forbidden energy gap in Ge is 0.72 eV, given, $hc$ = 12400 eV-$\mathring{\mathrm{A}}$. The maximum wavelength of radiation that will generate electron hole pair is
A) 172220 $\mathring{\mathrm{A}}$
B) 172.2 $\mathring{\mathrm{A}}$
C) 17222 $\mathring{\mathrm{A}}$
D) 1722 $\mathring{\mathrm{A}}$
Explanation
(c) Energy gap,$\ E_{g} = \frac{hc}{\lambda}$
$\lambda = \frac{hc}{E_{g}} = \frac{12400}{0.72} = 17222\ \mathring{\mathrm{A}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.